The rest of the website at the moment seems ok but I'm not sure why but when going to checkout on my site I get the following below. Please if anyone can help it would be much appreciated.
( a bit of background - I have upgraded core from 8.9.19 to 9.2.6 and commerce from 2.23 to 2.27 among other modules. I have another site that I did something similar but there is no problem with checkout).
The website encountered an unexpected error. Please try again later.
Error: Call to a member function getId() on null in Drupal\commerce_payment\Plugin\Commerce\CheckoutPane\PaymentInformation->buildPaneForm() (line 195 of modules/contrib/commerce/modules/payment/src/Plugin/Commerce/CheckoutPane/PaymentInformation.php).
Drupal\commerce_payment\Plugin\Commerce\CheckoutPane\PaymentInformation->buildPaneForm(Array, Object, Array) (Line: 546)
Drupal\commerce_checkout\Plugin\Commerce\CheckoutFlow\CheckoutFlowWithPanesBase->buildForm(Array, Object, 'order_information')
call_user_func_array(Array, Array) (Line: 532)
Drupal\Core\Form\FormBuilder->retrieveForm('commerce_checkout_flow_multistep_default', Object) (Line: 278)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 219)
Drupal\Core\Form\FormBuilder->getForm(Object, 'order_information') (Line: 143)
Drupal\commerce_checkout\Controller\CheckoutController->formPage(Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 578)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 158)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 80)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 717)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)